- Archaeological excavations are crucial sources for understanding the history and culture of ancient Tamilagam. - Sites like Uraiyur and Tirukkampuliyur provide tangible evidence of trade networks, including contacts with the Roman Empire. - Sites in the Kaveri delta region, like Thanjavur and Uraiyur, illuminate the early historical culture of the area. - Some ancient urban centres in Tamil Nadu also had a presence of heterodox religions like Buddhism and Jainism.